Production of pethidine hydrohalides, comprises debenzylation of new 4-ethoxycarbonyl-1-benzyl-1-methyl-4-phenyl-piperidine hydrohalide, useful as analgesics

摘要

Pethidine hydrochloride or hydrobromide (I) is produced by catalytic hydrogenation of a corresponding 4-ethoxycarbonyl-1-benzyl-1-methyl-4-phenyl-piperidine chloride or bromide (II) in a protic polar solvent. Production of pethidine hydrochloride or hydrobromide of formula (I) comprises the catalytic hydrogenation of a 4-ethoxycarbonyl-1-benzyl-1-methyl-4-phenyl-piperidine chloride or bromide of formula (II) in a protic polar solvent at 20 deg C to the b. pt of the solvent. X = Cl or Br. Independent claims are also included for: (1) 4-ethoxycarbonyl-1-benzyl-1-methyl-4-phenyl-piperidine chloride and bromide (II); and (2) the preparation of 4-(cyano or ethoxycarbonyl)-1-benzyl-1-methyl-4-phenyl-piperidine chloride or bromide of formula (II') by reaction of a 4-(cyano or ethoxycarbonyl)-1-benzyl-4-phenyl-piperidine of formula (III) with methyl chloride or bromide (IV) in the presence or absence of a protic polar solvent at -10 deg C to the b. pt. of the solvent. Y, Z' = CN or COOCH2CH3.